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bio.c revision 1.6.6.2
      1 /*	$NetBSD: bio.c,v 1.6.6.2 2008/04/05 23:33:20 mjf Exp $ */
      2 /*	$OpenBSD: bio.c,v 1.9 2007/03/20 02:35:55 marco Exp $	*/
      3 
      4 /*
      5  * Copyright (c) 2002 Niklas Hallqvist.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 /* A device controller ioctl tunnelling device.  */
     29 
     30 #include <sys/cdefs.h>
     31 __KERNEL_RCSID(0, "$NetBSD: bio.c,v 1.6.6.2 2008/04/05 23:33:20 mjf Exp $");
     32 
     33 #include "opt_compat_netbsd.h"
     34 
     35 #include <sys/param.h>
     36 #include <sys/conf.h>
     37 #include <sys/device.h>
     38 #include <sys/event.h>
     39 #include <sys/ioctl.h>
     40 #include <sys/malloc.h>
     41 #include <sys/queue.h>
     42 #include <sys/systm.h>
     43 #include <sys/mutex.h>
     44 #include <sys/proc.h>
     45 #include <sys/kauth.h>
     46 
     47 #include <dev/biovar.h>
     48 
     49 struct bio_mapping {
     50 	LIST_ENTRY(bio_mapping) bm_link;
     51 	struct device *bm_dev;
     52 	int (*bm_ioctl)(struct device *, u_long, void *);
     53 };
     54 
     55 static LIST_HEAD(, bio_mapping) bios = LIST_HEAD_INITIALIZER(bios);
     56 static kmutex_t bio_lock;
     57 static bool bio_lock_initialized = false;
     58 
     59 static void	bio_initialize(void);
     60 static int	bioclose(dev_t, int, int, struct lwp *);
     61 static int	bioioctl(dev_t, u_long, void *, int, struct lwp *);
     62 static int	bioopen(dev_t, int, int, struct lwp *);
     63 
     64 static int	bio_delegate_ioctl(void *, u_long, void *);
     65 static struct	bio_mapping *bio_lookup(char *);
     66 static int	bio_validate(void *);
     67 
     68 void	bioattach(int);
     69 
     70 const struct cdevsw bio_cdevsw = {
     71         bioopen, bioclose, noread, nowrite, bioioctl,
     72         nostop, notty, nopoll, nommap, nokqfilter, D_OTHER | D_MPSAFE
     73 };
     74 
     75 
     76 static void
     77 bio_initialize(void)
     78 {
     79 	if (bio_lock_initialized)
     80 		return;
     81 
     82 	mutex_init(&bio_lock, MUTEX_DEFAULT, IPL_VM);
     83 	bio_lock_initialized = true;
     84 }
     85 
     86 void
     87 bioattach(int nunits)
     88 {
     89 	int maj;
     90 
     91 	if (!bio_lock_initialized)
     92 		bio_initialize();
     93 
     94 	maj = cdevsw_lookup_major(&bio_cdevsw);
     95 	device_register_name(makedev(maj, 0), NULL, true, DEV_DISK, "bio");
     96 }
     97 
     98 static int
     99 bioopen(dev_t dev, int flags, int mode, struct lwp *l)
    100 {
    101 	return 0;
    102 }
    103 
    104 static int
    105 bioclose(dev_t dev, int flags, int mode, struct lwp *l)
    106 {
    107 	return 0;
    108 }
    109 
    110 static int
    111 bioioctl(dev_t dev, u_long cmd, void *addr, int flag, struct  lwp *l)
    112 {
    113 	struct bio_locate *locate;
    114 	struct bio_common *common;
    115 	char name[16];
    116 	int error;
    117 
    118 	switch(cmd) {
    119 	case BIOCLOCATE:
    120 	case BIOCINQ:
    121 	case BIOCDISK:
    122 	case BIOCDISK_NOVOL:
    123 	case BIOCVOL:
    124 #ifdef COMPAT_30
    125 	case OBIOCDISK:
    126 	case OBIOCVOL:
    127 #endif
    128 		error = kauth_authorize_device_passthru(l->l_cred, dev,
    129 		    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF, addr);
    130 		if (error)
    131 			return error;
    132 		break;
    133 	case BIOCBLINK:
    134 	case BIOCSETSTATE:
    135 	case BIOCVOLOPS:
    136 		error = kauth_authorize_device_passthru(l->l_cred, dev,
    137 		    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF, addr);
    138 		if (error)
    139 			return error;
    140 		break;
    141 	case BIOCALARM: {
    142 		struct bioc_alarm *alarm = (struct bioc_alarm *)addr;
    143 		switch (alarm->ba_opcode) {
    144 		case BIOC_SADISABLE:
    145 		case BIOC_SAENABLE:
    146 		case BIOC_SASILENCE:
    147 		case BIOC_SATEST:
    148 			error = kauth_authorize_device_passthru(l->l_cred, dev,
    149 			    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF, addr);
    150 			if (error)
    151 				return error;
    152 			break;
    153 		case BIOC_GASTATUS:
    154 			error = kauth_authorize_device_passthru(l->l_cred, dev,
    155 			    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF, addr);
    156 			if (error)
    157 				return error;
    158 			break;
    159 		default:
    160 			return EINVAL;
    161 		}
    162 		break;
    163 	}
    164 	default:
    165 		return ENOTTY;
    166 	}
    167 
    168 	switch (cmd) {
    169 	case BIOCLOCATE:
    170 		locate = addr;
    171 		error = copyinstr(locate->bl_name, name, sizeof(name), NULL);
    172 		if (error != 0)
    173 			return error;
    174 		locate->bl_cookie = bio_lookup(name);
    175 		if (locate->bl_cookie == NULL)
    176 			return ENOENT;
    177 		break;
    178 
    179 	default:
    180 		common = addr;
    181 		mutex_enter(&bio_lock);
    182 		if (!bio_validate(common->bc_cookie)) {
    183 			mutex_exit(&bio_lock);
    184 			return ENOENT;
    185 		}
    186 		mutex_exit(&bio_lock);
    187 #ifdef COMPAT_30
    188 		switch (cmd) {
    189 		case OBIOCDISK: {
    190 			struct bioc_disk *bd =
    191 			    malloc(sizeof(*bd), M_DEVBUF, M_WAITOK|M_ZERO);
    192 
    193 			(void)memcpy(bd, addr, sizeof(struct obioc_disk));
    194 			error = bio_delegate_ioctl(common->bc_cookie,
    195 			    BIOCDISK, bd);
    196 			if (error) {
    197 				free(bd, M_DEVBUF);
    198 				return error;
    199 			}
    200 
    201 			(void)memcpy(addr, bd, sizeof(struct obioc_disk));
    202 			free(bd, M_DEVBUF);
    203 			return 0;
    204 		}
    205 		case OBIOCVOL: {
    206 			struct bioc_vol *bv =
    207 			    malloc(sizeof(*bv), M_DEVBUF, M_WAITOK|M_ZERO);
    208 
    209 			(void)memcpy(bv, addr, sizeof(struct obioc_vol));
    210 			error = bio_delegate_ioctl(common->bc_cookie,
    211 			    BIOCVOL, bv);
    212 			if (error) {
    213 				free(bv, M_DEVBUF);
    214 				return error;
    215 			}
    216 
    217 			(void)memcpy(addr, bv, sizeof(struct obioc_vol));
    218 			free(bv, M_DEVBUF);
    219 			return 0;
    220 		}
    221 		}
    222 #endif
    223 		error = bio_delegate_ioctl(common->bc_cookie, cmd, addr);
    224 		return error;
    225 	}
    226 	return 0;
    227 }
    228 
    229 int
    230 bio_register(struct device *dev, int (*ioctl)(struct device *, u_long, void *))
    231 {
    232 	struct bio_mapping *bm;
    233 
    234 	if (!bio_lock_initialized)
    235 		bio_initialize();
    236 
    237 	bm = malloc(sizeof(*bm), M_DEVBUF, M_NOWAIT|M_ZERO);
    238 	if (bm == NULL)
    239 		return ENOMEM;
    240 	bm->bm_dev = dev;
    241 	bm->bm_ioctl = ioctl;
    242 	mutex_enter(&bio_lock);
    243 	LIST_INSERT_HEAD(&bios, bm, bm_link);
    244 	mutex_exit(&bio_lock);
    245 	return 0;
    246 }
    247 
    248 void
    249 bio_unregister(struct device *dev)
    250 {
    251 	struct bio_mapping *bm, *next;
    252 
    253 	mutex_enter(&bio_lock);
    254 	for (bm = LIST_FIRST(&bios); bm != NULL; bm = next) {
    255 		next = LIST_NEXT(bm, bm_link);
    256 
    257 		if (dev == bm->bm_dev) {
    258 			LIST_REMOVE(bm, bm_link);
    259 			free(bm, M_DEVBUF);
    260 		}
    261 	}
    262 	mutex_exit(&bio_lock);
    263 }
    264 
    265 static struct bio_mapping *
    266 bio_lookup(char *name)
    267 {
    268 	struct bio_mapping *bm;
    269 
    270 	mutex_enter(&bio_lock);
    271 	LIST_FOREACH(bm, &bios, bm_link) {
    272 		if (strcmp(name, bm->bm_dev->dv_xname) == 0) {
    273 			mutex_exit(&bio_lock);
    274 			return bm;
    275 		}
    276 	}
    277 	mutex_exit(&bio_lock);
    278 	return NULL;
    279 }
    280 
    281 static int
    282 bio_validate(void *cookie)
    283 {
    284 	struct bio_mapping *bm;
    285 
    286 	LIST_FOREACH(bm, &bios, bm_link)
    287 		if (bm == cookie)
    288 			return 1;
    289 
    290 	return 0;
    291 }
    292 
    293 static int
    294 bio_delegate_ioctl(void *cookie, u_long cmd, void *addr)
    295 {
    296 	struct bio_mapping *bm = cookie;
    297 
    298 	return bm->bm_ioctl(bm->bm_dev, cmd, addr);
    299 }
    300